共查询到19条相似文献,搜索用时 249 毫秒
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采用软开关技术可以有效克服功率变换器的开关损耗。介绍了软开关脉宽调制DC/DC全桥变换器的实现原理,给出了多种零电压开关(ZVS)和零电压零电流开关(ZVZCS)变换器的电路拓扑,分析了它们的性能特点和结构优缺点,指出了零电压零电流开关脉宽调制DC/DC全桥变换器在中、大功率场合会有很好的应用前景。 相似文献
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PWM加相移控制的双向DC/DC变换器 总被引:4,自引:13,他引:4
该文提出了一种PWM加相移控制的双向DC/DC变换器。该变换器结合了PWM和相移这两种控制技术优点,不但可以减小变换器的电流应力和通态损耗,而且可以拓宽零电压开关的范围。该文详细地介绍和分析了变换器的工作原理,给出零电压开关的条件,最后给出了实验结果。 相似文献
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针对普通升压变换器输出电压低及开关损耗大的问题,本文提出一种新型零电压关断高增益DC/DC变换器。文中首先对1个工作周期内不同状态下工作状况进行了分析,然后对所提变换器性能特点进行分析并计算给出电压增益比与开关二极管的电压及电流应力。理论分析表明,所提方案有效提高了变换器输入输出增益及工作效率,且开关管的电压及电流应力得到有效降低。最后,通过1台功率为800 W的实验样机进行了验证和相应的损耗分析,实验结果证明了理论分析的正确性。 相似文献
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为进一步提高全桥DC/DC变换器的效率,提出了一种基于耦合电感式缓冲电路全软开关DC/DC变换器FSSC-ICIS(full-soft-switching DC/DC converter with integrated coupled inductor snubbers)。该变换器将全桥电路与软开关辅助网络相结合,控制策略采用最简单的互补对称控制。改进的变换器不仅实现主开关管的零电压开关ZVS(zero-voltage-switching)开通与零电流开关ZCS(zero-current-switching)关断和整流二极管的ZCS开通与关断,辅助网络也能够实现其自身开关管的软开关。通过实验样机验证了所提出变换器的正确性与可行性,实验结果表明,所提出的结构能够实现所有开关器件的软开关。 相似文献
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本文简述了零电流DC/DC变换器中的电流电压函数关系和基本原理,深入讨论了同步整流技术应用于零电流DC/DC变换器存在的困难,以及实现的可行性,提出了初步的解决方案。 相似文献
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与传统的Buck电路相比,基于H桥并联的DC/DC变换器可以实现电压的双极性输出和故障时的冗余控制,非常适合用于大功率电动机正反转控制的场合。分析了并联H桥型DC/DC变换器的结构组成和双脉宽调制(PWM)模式。为了降低双脉宽调制下H桥型DC/DC变换器的开通和关断损耗,对无源软开关技术进行了分析,重点探讨了RCD缓冲电路和最小应力缓冲电路之间的性能差异,指出最小应力软开关技术可以获得更好的软开关性能,并就将其用于双脉宽调制下的并联H桥DC/DC变换器进行了仿真研究。仿真结果表明:最小应力软开关技术用于双脉宽调制下并联H桥DC/DC变换器时,可以实现开关管的零电压开通和零电流关断。 相似文献
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Nor Azura Samsudin Shahid Iqbal Soib Taib 《IEEJ Transactions on Electrical and Electronic Engineering》2016,11(5):648-654
This paper proposes a novel zero‐current‐switching series resonant high‐voltage DC–DC converter with reduced component count. The series resonant inverter in the proposed topology has two power switches (insulated‐gate bipolar transistors, IGBTs), two resonant capacitors, and only one high‐voltage transformer (HVT) with center‐tapped primary windings. The power switches are connected in the form of a half‐bridge network. The leakage inductances of the transformer's primary windings together with the resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating the power switches with interleaved half switching cycle. The secondary winding of the HVT is connected to a bridge rectifier circuit to rectify the secondary voltage. The converter operates in the discontinuous conduction mode (DCM) and its output voltage is regulated by pulse frequency modulation. Therefore, all the power switches turn on and off at the zero‐current switching condition. The main features of the proposed converter are its lower core loss, lower cost, and smaller size compared to previously proposed double series resonant high voltage DC–DC converters. The experimental results of a 130‐W prototype of the proposed converter are presented. The results confirm the excellent operation and performance of the converter. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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《International Journal of Circuit Theory and Applications》2017,45(1):120-132
In this paper, a half‐bridge resonant DC/DC converter with constant output voltage is proposed, which possesses good soft‐switching characteristics. At rated operating point, the switches can operate almost without switching‐on and off losses. Further, at whole working range, both zero‐voltage‐switching mode of switches and zero‐current‐switching mode of diodes are maintained. Thus, the converter can achieve a high efficiency. Experimental results verify the low switching losses and high efficiency characteristics based on a 200 W prototype. System efficiency is as high as 96% and always above 90% when output power changes from 100% to 20%. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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隔离型DC/DC变换器连接低压直流配电网和用户侧直流负荷,在低压直流配电系统中起着重要作用, 对其效率和功率密度提出更高的要求。本文采用具有原边开关管零电压开通和副边整流管零电流关断特性的LLC谐振变换器,首先分析变换器的工作原理,对其谐振参数进行选择。使用具有更低的导通电阻和等效输出电容的氮化镓器件作为原边开关管,进一步提高变换器工作频率和效率,降低磁性元件体积。在此基础上,对GaN器件驱动、同步整流和磁性元件进行优化和设计。最后搭建了一台375V/48V/500W的LLC谐振变换器样机,最高效率为97.6%,验证了设计的正确性。 相似文献
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Bor‐Ren Lin Chung‐Wei Chu 《International Journal of Circuit Theory and Applications》2016,44(5):996-1011
In this paper, a new soft switching direct current (DC)–DC converter with low circulating current, wide zero voltage switching range, and reduced output inductor is presented for electric vehicle or plug‐in hybrid electric vehicle battery charger application. The proposed high‐frequency link DC–DC converter includes two resonant circuits and one full‐bridge phase‐shift pulse‐width modulation circuit with shared power switches in leading and lagging legs. Series resonant converters are operated at fixed switching frequency to extend the zero voltage switching range of power switches. Passive snubber circuit using one clamp capacitor and two rectifier diodes at the secondary side is adopted to reduce the primary current of full‐bridge converter to zero during the freewheeling interval. Hence, the circulating current on the primary side is eliminated in the proposed converter. In the same time, the voltage across the output inductor is also decreased so that the output inductance can be reduced compared with the output inductance in conventional full‐bridge converter. Finally, experiments are presented for a 1.33‐kW prototype circuit converting 380 V input to an output voltage of 300–420 V/3.5 A for battery charger applications. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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一种新型二极管辅助换流网络软开关PWM全桥变换器 总被引:1,自引:1,他引:0
本文提出了一种新的软开关拓扑结构,利用二极管辅助谐振换流网络(DARCN-Diode Auxiliary Resonant Commutating Network)来使DC/DC全桥变换器的主开关工作到零电压开通状态,同时可使DARCN中的辅助二极管以及逼边整流二极管实现软关断,全桥变换器的控制信号对普通PWM硬开关变换器完全一样,文中对它的实现原理进行了理论分析,使用PSpice对电路进行了仿真,并进行了实验,验证了电路原理的正确性,并分析了电路参数对软开关实现及电路性能的影响。 相似文献
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基于变频控制的串联谐振DC/DC变换器的研究 总被引:1,自引:0,他引:1
串联谐振DC/DC变换器具有电路结构简单、在全输入和全负载范围内可实现开关管的ZVS、功率转换效率高等优点,是目前开关电源研究的热点之一。本文分析了基于变频控制的串联谐振DC/DC变换器的工作原理,阐明了变换器在三种不同开关频率下的工作特性,定量地给出了不同工作状态下变换器的输入电压、输出电压、开关频率以及谐振电感等参数之间的关系式。在一台1.5KW原理样机上的实验结果表明,该变换器变换效率最高可达96.3%,所有开关管实现ZVS,不同工作状态时变换器输入输出电压等参数关系与理论分析一致。 相似文献
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This paper presents a new DC/DC converter with series half‐bridge legs for high voltage application. Two half‐bridge legs connected in series and two split capacitors are used in the proposed circuit to limit the voltage stress of each active switch at one‐half of input voltage. Thus, active switches with low voltage stress can be used at high DC bus application. In the proposed converter, two circuit modules are operated with an interleaved pulse‐width modulation scheme to reduce the input and output ripple currents and to achieve load current sharing. In each circuit module, two resonant tanks are operated with phase‐shift one‐half of switching cycle such that the frequency of the input current is twice the frequency of the resonant inductor current. Based on the resonant behavior, all MOSFETs are turned on at zero voltage switching with the wide ranges of input voltage and load conditions. The rectifier diodes can be turned off at zero current switching if the switching frequency is less than the series resonant frequency. Thus, the switching losses on power semiconductors are reduced. The proposed converter can be applied for high input voltage applications such as three‐phase 380‐V utility system. Finally, experiments based on a laboratory prototype with 960‐W rated power are provided to demonstrate the performance of proposed converter. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献